The effects of spatial and social density whall be examined on seven to ten year old children with attention to individual differences in response to crowded conditions. These individual variables include sex, motor inhibition, impulsivity, personal space, and teacher ratings of aggression, anxiety, hyperactivity, and behavior disturbance. Comparative effects of spatial density (varying amount of space while keeping numbers of children constant) and social density (varying number of children while keeping area constant) shall be made to determine the role that area/person versus numbers of people make in behavior. Dependent variables include degree of social involvement (solitary, onlooker, social interacter), aggression and aggressive play, number of interruptions of toy activity, number of escape behaviors, affect, number of children played with, helping behaviors, activity level, motoric position (standing, lying, walking, running, sitting), and number of different activities engaged in. Order effects comparing increasing and decreasing density shall also be determined. The research shall be experimentally controlled in a playroom laboratory setting where the children's behaviors shall be rated by research assistants behind one-way mirrors. These findings shall then be compared to those obtained in the experiments done in the first year of the research project, where four and five year old boys and girls of far and close personal space were studied. BIBLIOGRAPHIC REFERENCES: "The psychological study of crowding: Some historical roots and conceptual developments" has been published in the American Behavioral Scientist, 18:6, July-August, 1975 and "Beyond the effects of crowding; Situational and individual differences" is in press as a chapter of a book entitled Psychological Perspectives on Environment and Behavior: Conceptual and Empirical Trends, edited by D. Stokols, published by Plenum Press.